Grinding machine



June 24, m1.. c. G. FLYGARE 2,247,228

GRINDING MACHINE Filed Oct. 2. 1939 5 Sheets-Sheet 1 we y ,'32 -44 76- June 24, WM.. c, G, FLYGARE GRINDING MACHINE s sheets-shea 2f Filed 001:. 2. 1959 CHRL EF1. V55/RE June 24, 1941., C, FLYGARE 2,247,228

` GRINDING MACHINE Filed Oct. 2, 1939 5 Sheets-Sheet 5 IBB JIH'

' HB Hq 100 Patented June Z4, 1941 srs GRNDNG MACHINE Carl G. Flygare, Worcester, Mass., assignor to Norton Company, Worcester, Mass., a corporation of Massachusetts Claims.

The invention relates to grinding machines, and more particularly to a cylindrical type grinding machine for automatically grinding a cylindrical face and a fillet or radius adjacent thereto on a work piece, such as a piston ring.

One object of the invention is to provide a simple and thoroughly practical grinding machine for automatically grinding a cylindrical type work piece having a fillet or radius formed adjacent to one or both ends thereof. Another object of the invention is to provide a grinding machine for grinding a true cylindrical surf-ace on a work piece and then swinging the work piece to grind a fillet thereon adjoining said cylindrical surface. A further object of the invention is to provide such a grinding machine which is arranged to grind a cylindrical work piece and then to form a radius or fillet adjoining each end of the cylindrical face.

Another object of the invention is to grind a v cylindrical face on a work piece while the axis of the work piece is maintained substantially parallel to the axis of the grinding wheel and then to swing the axis of the work piece to produce a llet or radius adjoining the end of said cylindrical face. A further object of the invention is to provide apparatus for grinding a cylindrical face on a work piece while maintaining the axis of the work piece substantially parallel to the axis of the grinding wheel and then to swing the axis of the work piece to produce a radius or fillet adjacent to and adjoining said cylindrical face and then to shift the work piece in an axial direction and again to swing the axis thereof to produce a fillet or radius adjacent to and adjoining the other end of said cylindrical face. Other objects will be in part obvious or in part pointed out hereinafter.

The invention accordingly consists in the features of construction, combinations of elements, and arrangements of parts, as will be exemplified in the structure to be hereinafter described, and the scope of the application of which will be indicated in the following claims.

ln the accompanying drawings, in which is shown one of various` possible embodiments of the mechanical features of this invention- Fig. 1 is a front elevation of the improved grinding machine;

Fig. 2 is a diagrammatic View of the various mechanisms of the machine, showing the piping diagram and the electrical diagram for automatically controlling the grinding cycle;

Fig. 3 is a fragmentary sectional View, on an enlarged scale, taken approximately on the line 3-3 of Fig. 2;

Fig. 4 is a fragmentary plan view of the mechanism for actuating the table reversing mechanism in timed relation with the swivelling of the work support;

Fig. 5 is a vertical sectional View through the table reversing valve, on an enlarged scale; and

Fig. 6 is a fragmentary cross-sectional view, taken approximately on the line G-S of Fig. 5, through the table reversing valve, showing the construction of the speed control valve associated therewith.

The improved grinding machine has been illustrated in the drawings, comprising a base lo which supports a longitudinally reciprocable work supporting table II on the usual V-way I2 and flat way I3 (Fig. 3). The table II serves as a rotatable support for a work piece, such as a piston ring I5 which is mount-ed on a supporting arbor l5. A rotatable work support is provided, comprising a headstock I'I having a headstock center i8 to support the left-hand end of the arbor I6 (Figs. 1 and 2). The headstock Il is preferably a motor driven headstock in which an electric motor I9 is mounted on the upper surface of the headstock l1. The motor is connected by means of a multiple V-belt drive 2l! with a. headstock spindle 2 l.

The right-hand end of the work supporting arbor I6 is supported by means of a footstock 23 having a work supporting center 2d mounted therein which is arranged to engage and rotatably support the footstock end of the arbor i6.

The table II is arranged so that it may be traversed longitudinally, either manually or by power. A manually operable traverse mechanism may comprise a manually operable rotatable hand wheel 25 which is rotatably supported 0n a shaft 26. A gear 2l is also carried by the shaft 26 and is arranged to rotate with the hand wheel 25. The gear 2l meshes with a large gear 28 which is supported on a shaft 29 rotatably mounted in the base I0 of the machine. The shaft 29 also supports a gear 3i) which is preferably formed integral with or xedly mounted to turn with the gear 28. The gear Sil meshes with a rack bar 3| depending from the under side of the table Il. By rotation of the hand wheel 25 in either direction, a correspond ing traversing movement may be imparted to the table il. The power operated mechanism for traversing the work supporting table II longitudinally and automatically will be hereinafter described.

A transversely movable rotatable grinding wheel 3) is rotatably supported on a transversely movable wheel slide 3l which is in turn supported on the usual V and flat ways (not shown) formed on the upper surface of the base l!) and is arranged for a transverse feeding movement whereby the grinding wheel 38 may be fed transversely toward or from the work piece l5 as desired. The wheel 3% is preferably driven by means of an electric motor 32 mounted on the upper surface of the wheel slide 3l. The motor is provided with a multiple V-groove driving pulley 33 which is connected by multiple V-belts 3d with a multi-groove pulley 35 mounted on the outer end of a wheel spindle 3% which supports the grinding wheel 35i at its other end.

Wheel feed mechanism A wheel feeding mechanism is provided for feeding the grinding wheel either manually or by power toward and from the work. The wheel feeding mechanism is substantially identical with that shown in the prior U. S. patent tol H. A. Silven No. 2,623,764 dated December 10, 1935. A 'half nut i3 (shown diagrammatically in Fig. 2 as mounted on the side of the slide 3 l) is mountedv on the under side of the wheel slide 3l. and meshes with or engages a rotatable cross feed screw di. The feed screw il is rotatably supported in bearings (not shown) in the base lil. A forwardly extending projection 4E of the feed screw lli; is slidably keyed within an ap-erture (not shown) in the end of a rotatable shaft 43 which projects from the front of the machine base. The shaft i3 is rotatably mounted in bearings (not shown) within the base l0. The shaft d3. is provided at its outer end with a gear Ml which meshes with av gear 45. The gear 15. is mounted. to rotate with a manually operable rotatable feed Wheel lill. The feed` wheel 45 is provided witha micrometer feed adjusting mechanism il which is substantially identicalV withv that shown. in the above-mentioned prior U. S. patent. The micrometer adjustment serves precisely to adjust a stop abutment relative to the manually operable feed. wheel it to compensate for grinding wheel wear.

Inv the preferred. construction the wheel slide 3i is arranged so that it may be moved toward and from the work piece i5 to grind the same to a predetermined size by means of a iiuid pressure. actuated feeding mechanism. As illustrated in the drawings, the rear end of the feed. screw il is supported in a slidably keyed bearing member d'3 which is slidably supported within a casing 51S on the base l@ of the machine. A duid pressure cylinder 5S is attached to or formed integral with the casing is and contains a slid.- ably mounted. piston 5l which is connected by means of a piston rod t2 with the bearing meinber t8, and is arranged so that when fluid under pressure is admitted to a cylinder chamber 53, the piston 5l will be moved upwardly into its rearward or inoperative position, transmitting a corresponding movement through the feed screw ill, the half nut fifi, to move the wheel slide 3l and the grinding wheel 3@ rearwardly to. an inoperative position. Similarly, when iiuid under pressure is admitted to a cylinder chamber 59,

a rapid approaching movement of the grinding wheel 3% (in a downward direction, Fig. 2) is provided.

A fluid pressure system is. provided to supply fluid under pressure for moving the piston 5.1i soY as to cause either an infeeding or outfeeding movement of the grinding wheel. This system may comprise a reservoir 65! which is formed as a box-like section within the base Il). Fluid is drawn from the reservoir til through a pipe El by means of a motor driven fluid pressure pump S2. rihe pump $2 forces fluid under pressure through a pipe 63 to a wheel feed control valve 5G. The control valve (ill is preferably a piston type valve, comprising a valve stem 55 having formed integrally therewith valve pistons and Sl. Fluid under pressure passing through the pipe 53 enters a valve chamber located between the valve pistons E5 and 5l and passes through a passage t@ into the cylinder chamber 53 to move the piston El!Y to its rearward position with the grinding wheel 3E?` separated from the work piece i5, as indicated in the drawings. During the rearward movement of the piston 5l fluid is eX- hausted from the cylinder chamber 5S through a passage E9 into a valve chamber located betweenA the valve piston 6l and the end of the valve casing, and out through a pipe lll which exhausts` iluidinto the reservoir 69. The valve stern is arranged so that it may be moved endwise to shift the valve Sfiinto a reverseposition so as to cause either a forward or rearward feeding movement of thegrinding wheel 3i).

A spring li is4 provided to maintain the valve Si. normally in its uppermost position (Fig. 2). An electric solenoid l2 is mounted within the base lll and is operatively connected to shift the valve 6I! downwardly (Fig. 2) against the compression of the spring li. if desired, a fluid pressure controlled feed regulating mechanism having a positive stop may be provided for reducing the rapid approaching movement caused by the pistons 5oA to a slow grinding feed. This mechanism is not considered to be a part of the present invention and consequently hasnot been illustrated in detail. For details of disclosure as1 to the dash pot feed regulator, reference may be had to the above-mentioned U. S. patent to Silven No. 2,023,704., above referred to.

The feeding mechanism is preferably electrica-lly controlled. and le are mounted on the front of the machine base. and are arranged to be actuated by means of a pivotally mounted control lever 'Il (Fig. 1').` The push buttons 'i5 and le. are connected with power lines and are connected to control an adjustable electrical time delay relay lil. When the lever il is actuated to initiate a forward feedingA movement of the grinding wheel, thetime delay relay 'i3 is set in motion and also the solenoid 7.2'is energizedto shift the feed control: valve 6G: into a forward. feeding position, such as that shownin Fig. 2. The time delay relay ll is set to cover the over-all grinding cycle and, to deenergize the solenoid 'l2v after a predetermined time interval has elapsed to release the comp `ession of the spring H to reverse the movement of the grinding wheel 30 and thereby shift the grinding wheel rearwardly to an inoperative position.

Worlt idole reciprocation A pair of push buttons 'I5 by a pair of hollow piston rods 83 and 84, respectively, with a pair of hollow brackets 85 and 85, respectively, which are xedly mounted on opposite ends of the base Iii. The table traversing or reciprocating mechanism utilized in the present disclosure is identical with that shown in the prior U. S. patent to W. H, Wood No. 2,071,677 dated February 23, 1937, to which reference may be had for details of disclosure not contained herein. Fluid under pressure from the pump t2 within the base |i of the machine forces fluid through the pipe lit and through a pip-e 87| and a valve 83 which is actuated by means of a solenoid |19 and through a pipe 9d to a directional control valve Si. The directional valve serves to admit uid under pressure either to the table traverse cylinder 80 above referred to or to another fluid pressure system for swivelling the work support to be hereinafter described.

The directional valve 9| is a piston type valve comprising a valve stem 92 having formed integrally therewith valve pistons 93 and A spring 95 serves normally to hold the valve s ern 5&2 in an upward direction (Fig. 2), that is, in position for traversing the work supporting table A solenoid 96 is connected to the other end of the valve stem 92 and serves when energized to shift the valve stem 92 downwardly (Fig. 2) to cut oii iiuid iow to the table traverse mechanism and to admit fluid under pressure to the Work supporting swivelling system to be hereinafter described. In the position of the directional valve (Fig. 2) fluid under pressure passing through the pipe Sti enters a valve chamber located between the valve pistons 93 and @Il and passes out through a pipe 9i, a throttle valve 98, and a pipe 99 to a table control valve unit iii). The valve S8 serves to regulate the flow of fluid through the pipe 29 as desired.

The valve unit lill), as shown diagrammatically O in Figl 2, comprises a stop and start valve le! and also a reversing valve |96 whereby the direction of flow of fluid to the table cylinder may be automatically controlled. The valve serves as a stop and start valve as well as a speed control valve for the table traversing movement. When the valve stem is rotated by means of a knob |82, a v-port to be hereinafter described serves to regulate the ow of fluid. The valve piston |23 is also arranged for a longitudinal sliding movement by means of a manually operable control lever |513 (Figs. 1 and 2) which is pivotally mounted by means of a stud m5 on the front of the machine base. When the lever idd is moved in a clockwise direction the valve m3 will be closed, thus stopping the traversing movement of the table when desired. The valve unit it also contains a reversing valve iii which is arranged to convey fluid either through a pipe HB1 to a cylinder chamber |08 or through a pipe HB9 into a cylinder chamber lli) to control the direction of movement of the table The constructional details of the valve mechanisin |043 have been illustrated in Figs. 5 and 6. The reversing valve (Fig. 5) comprises a valve stem having formed integrally therewith valve pistons H2, H3, lili, H5 and H6. The valve stem |ii| is provided with a valve piston l i3 having a V-groove H9 formed therein. In the position illustrated in Fig. 6 the V-port allows full exhaust of fluid from the cylinder chamber. When the knob m2 is rotated the V-port cuts olf more or less of the port aperture and thus controls and regulates the longitudinal movement of the table l, A detailed description of fil) this valve mechanism and its operation is not deemed necessary in the present case since this mechanism and the operation thereof are fully disclosed in the prior patent to Wood No. 2,071,677 to which reference may be had for details of disclosure not contained herein.

The reversing valve is preferably actuated by means of a pivotally mounted reversing lever which is pivotally supported on a stud |2| on 0 the ront of the machine base. The upper end ci' the reversing lever |22 is provided with a stud |22 which is arranged to be actuated automaticaliy in a manner to be hereinafter described by movement of the work support.

A pawl and ratchet infeeding mechanism is provided for the grinding Wheel i5, which comprises a fluid pressure piston and cylinder mechanism contained Within a casing |23 which serves to reciprocate a feed pawl |24 to incrementally 0 rotate the feed wheel 46. This mechanism has not been illustrated in detail in the present case,

since it is not considered to be a part of the present invention and is identical with that shown in the above-mentioned prior patent to Wood No. 5 2,071,677 to which reference may be had for details of disclosure not contained herein. Each time the reversing lever lit is shifted to reverse the valves mt and ll, the hydraulic feed mechanism contained within the casing |23 actuates 0 the pawl lZfi to advance the wheel 3|) into the "work piece.

In order to attain the main object of the invention, the work piece l5 is held in position with u its axis substantially parallel to the axis of `the grinding wheel St to produce a true cylindrical surface on the periphery of the work piece l5. In order to grind a radius or llet at one or both ends of the cylindrical face, the work supporting member is preferably pivotally mounted so that the axis of the work piece may be swung about an axis which is normal to a plane passing through the axes of the grinding wheel and work piece to produce the desired curved face on the periphery of the work piece. A platen |25 is iixedly mounted on theupper surface of the table ii. The platen |25 serves as a support for a pivotally mounted frame |25 which is supported Jy means of a vertically arranged pivot stud |21 and is arranged to swing in a horizontal plane to shift the axis of the work piece i5 relative to the axis of the grinding wheel 3|] when desired. The frame |25 serves as a support for a transversely movable slide |28. An adjusting means is provided for the slide |23 comprising a screw |29 L which has one end fixedly mounted to the slide |23. The screw |29 passes through an aperture within a boss |t projecting upwardly from the frame |23. A pair of nuts |3| and |32 are screw threaded onto the screw |253 on opposite sides of the boss |33 and serve as push and pull nuts to adiust the position of the transverse slide |28 as desired. This adjustment is particularly adapted for providing a transverse adjustment of the work 5 support in setting up the machine for grinding with the center of the corner radius which it is desired to produce on the work piece. As above stated, in the preferred form it is desirable to adapt the mechanism for grinding a llet adjacent one or both ends of the cylindrical face on the work piece i5. It is, therefore, necessary rst to shift theI work piece i5 so that the center of one'f fillet coincides with the axis of the pivot |27` and whileV in this position to grind one of the fillets oni the work piece |5. It is then necessary to shift the work piece I5 longitudinally to bring the center of the other fillet into alignment with the axis of the pivot |27 before grinding the second fillet on the work piece. In order to facilitate this movement, a longitudinally movable shuttle table |55 is supported in a dovetailed way |351 formed on the upper face of the transverse slide |53. The upper portion of the shuttle table E55 is'similarly formed as a dovetailed way for supporting the headstock il and the fonts-took 25.

The plate which is fastened to the upper surface of the table is provided with a notch |38 which is arranged to be engaged by a slidably mounted locking plunger |39 (Fig. 4) which is carried by the pivotally mounted frame |25. The plunger 55' is normally heldin a latched position in engagement with the notch |38 by means av spring fia. A solenoid |55 is operatively connected through a pivotaily mounted rock arm ifiil pivoted on a stud |42 and connected at its other end by means of a link |45 automatically to withdrawl the plunger |59 to allow the frame |25 to swing to shift the axis of the rotatable work piece relative to the axis of the grinding wheel during the grinding operation to grind a radius or fillet adjacent to the cylindrical face thereon.

In order to shift the reversing valve at the ends of the work stroke, that is, when a fillet has been ground at one end of a work piece, a slidably mounted bar M5 is supported on the front edge of the table by means of studs M5 and Ill? which pass through elongated slots |53 and MS formed in the bar |515. The b-ar M5 is provided with a notch |55 in its under surface which engages the stud |22 projecting from the reversing lever |25. notch |55 so that the bar |45 may be moved longitudinally through a short distance before its motion is transmitted to rock the reversing lever |25.

The bar |45 is provided with adiustably positioned actuating rollers I5| and |52 which are supported by studs |53 and |54, respectively. The studs |53 and |54 are adjustable longitudinally relative to the bar |135 within elongated slots |55 and 55 formed in the end portions of the bar M5.

The under surface of the pivotally mounted frame |25 is provided with an arrowhead-shaped member |58 having cam faces |55 and E55 formed thereon. When the frame |26 is swung in a counterclockwise direction (Fig. 4), the cam face moves into position |5511. During this movement the cam face |5511 engages the roller |52 and slides the roller |52 and the bar |45 longitudinally toward the right (Figs. 1 and 4) to shift the reversing lever |25 into the position illustratedv in Fig. l. During this movement the axis of the work piece is swung relative to the axis of the grinding wheel to generate a radius or iillet adjacent to the right-hand end of the cylindrical face on the work piece i5. The frame |26 is then swung ina clockwise direction so that the cylindrical facesagain swung into-operative engagement with` the periphery of the grinding wheelt'udinally toward the right to shift the work piece so that the center of the illet or radius to be formedV at the left-hand end of the cylindrical faceon the work piece l5 is aligned with the axis of the pivot stud |21. The plunger |39 is then A clearance is provided inv the The shuttle table |55 is moved longiagain automatically withdrawn from the notch |58V by energizing the solenoid |46. The frame |25 is then swung in a clockwise direction so that the arrowhead |58 assumes the position |551) and the cam face |59'moves into position |591) in engagement with the roller |5|. Continued movement of the frame |25' in its movement in a clockwise direction (Fig. 4) shifts the arrowshaped' member |58 into position |550 and the cam face |59 into position |590, thus shifting the roller |5| into broken line position |5|a which shifts the bar |45 longitudinally toward the left (Figs. l and 4), which movement serves to shift the notch 53 so that it engages the stud |22 and rocks the reversing lever |26 in a counterclockwise direction (Fig. l), which movement serves to shift the valve stem I toward the right (Fig. 5) to shift the reversing valve into the reverse position and thus start the movement of the table in the reverse direction.

A fluid pressure mechanism is provided for swinging the frame |25 in timed relation with the other mechanisms of the machine. This mechanism comprises a fluid pressure cylinder V55 which is pivotally mounted by means of a stud il'i on a bracket V12 which is iixedly mounted at the riglit-handA end of the table il. The cylinder W0- contains a slidably mounted piston H3 andy is connected by means of a piston rod ill with a stud V15 which is Xedly supported relative to the swinging frame |25. When fluid under pressure is admitted through a pipe H5 into a cylinder chamber il?, the piston H3 and rod iid will be moved toward the right (Fig. 2) to swing the frame |26 in a counterclockwise direction to grind a llet at the right-hand end of the cylindrical portion on the Work piece E5.

Similarly, when fluid under pressure is forced through a pipe |78 into a cylinder chamber |79, the piston |173, piston rod |14 and stud |75 are moved toward the left (Fig. 2) to swing the frame |26 in aA clockwise direction to grind a fillet adjacent to the left-hand end of the work piece i5. Valves and |53!v are provided in the pipe lines V56 and |75, respectively, to facilitate adjustment of the flow of iiuid under pressure therethrough so that the speed of movement of the piston H3 and the swinging frame |25 may be readily controlled. A- suitable control valve unit |35 is provided for controlling the admission to and exhaust of fluid from the cylinder Vid; The control valve unit |85 is identical with the table control valve |55, consequently this valve is only shown diagrammatically in Fig. 2. The valve unit |85 includes a stop and start valve |55 whereby the cylinder |55 may be cut olf from the main uid pressure system, if desired, 'by moving the valve stem |86 longitudinally. The valve stem |35 serves also as a speed control valve, whereby the fluid passing therethrough `may be' throttied to govern the speed of movement of the frame EES during its swinging movement. TheY control'V valve unit |85 also includes a reversing valve |31 whereby the iiuid passing to and` from the cylinder V25 through the pipes H5 and l'lii", respectively, maybe reversed as desired.

It is desirable that the movement of the table i and the swivelling movement of the frame 25 bev synchronized so that one of said membersis inoperative while the other is operative and vice versa. In order to obtain this synchronization, the valve stem is operatively connected by means ofl a rod |83 to actuate the reversing valve |81 in timed relation With the table reversing valve |06 so that when the bar |45 carried by the table is shifted longitudinally at the ends of the oscillatory stroke of the frame |26 in either direction, the table reversing valve |06 and also the swivel reversing valve |01 are automatically shifted into their reverse positions.

The directional control Valve 9| is provided with a pipe |09 which is connected by means of a valve with a pipe |9| to convey fluid under pressure to the swivel control valve unit |05.

When the directional valve is positioned as shown in Fig. 2, with the valve pistons 03 and 94 in an upward position, uid is cut off from the pipe |89 and directed only through the pipe 91, valve 98 and pipe 99 to the table control valve unit |00.

The directional control valve |05 is operated in timed relation with the other units of the machine, so that when the solenoid 06 is automatically energized in timed relation with the other mechanisms of the machine the directional control valve 0| is moved downwardly (Fig. 2) to cut off fluid from the table control valve unit |00 and to pass fluid under pressure through the pipe |80, the valve |90, and the pipe I0| to the swivel control valve unit 85 to admit uid under pressure to one end or the other of the cylinder |10 to initiate a swivelling movement of the frame so as to grind a radius or fillet adjacent to one end of the cylindrical face on the work piece.

The shuttle table is moved relative to the table during the traversing movement of the latter. A pair of brackets 200 and 20|, respecively, are fastened to opposite ends of the shuttle table |35. The brackets 200 and 20| are provided with cam faces which are arranged to be engaged by rollers 202 and 203, respectively. The rollers 202 and 203 are supported by plunger-S 200 and 205, respectively, which are in turn supported by brackets 200 and 20|, respectively. fi

The brackets 206 and 201 are pivotally mounted on supporting plates 208 and 209 which are fixedly secured to the base I0. As the table is traversed longitudinally under the influence of fluid under pressure, the shuttle table |35 travels with the table until the cam face on the bracket 200 or 20| engages the rollers 202 or 203, respectively, which serves to hold the shuttle table together with the headetock and footstoclr and the work piece being ground stationary dur- 5,-'

ing the completion of the reciprocatory traverse of the table Il. The plungers 204 and 205 are preferably adjustably mounted so that the shuttle table will be accurately positioned at each end of its stroke so that the centers of the llets to be produced adjacent to one or each end of the cylindrical face on the work piece are successively aligned with the axis of the pivotal stud |21,

It is desirable to provide a suitable interlock and 2id which are arranged to actuate either the T' limit switch 2|0 or 2|! as the table is moved longitudinally.

Similarly, a pair of i normally open limit switches 2|5 and Zi are mounted on the table and are arranged to be actuated by adjustrectional control valve 9|.

able screws 2|'| and 2|B which are adjustably mounted on the front edge of the shuttle table |35. The limit switches 2|0 and 2|| are con-- nected in series with the limit switches Zlii and 2|0, respectively, and these limit switches are in turn connected to set in motion an electrical time delay relay 220 which serves to energize the solenoid |40 which serves to withdraw the locking plunger |30. Withdrawal of the plunger |30 serves to close a normally open limit switch 22| which closes a circuit to energize the solenoid 96 which shifts the directional control valve 0| to admit fluid under pressure to the swivel control valve unit |35 which in turn admits fluid under pressure to one end or the other of the cylinder |10 to swivel the axis of the work piece relative to the axis of the grinding wheel about the axis of the pivotal stud i2? so as to generate a fillet on the periphery of the work piece I5 adjacent to the end of the cylindrical face produced thereon.

The time relay 220 is adjusted so that the solenoid |00 will be energized a sufficient length of time for the frame 220 to start its pivotal motion, after which the time relay 2720 operates to deenergise the solenoid |50, thus allowing the locking plunger |39 to ride on the periphery of the arcuate surface 223 of the supporting plate |25 so that upon the return stroke the locking plunger |39 under the influence of an actuating spring |39a will return into engagement with the notch |33 formed in the plate |25. It will be readily apparent from the foregoing disclosure that the solenoid cannot be energized until the table has been shifted to close either the limit switch 2|0 or 2H, after which it is necessary for the shuttle table to move relative to the table to close either the limit switch 2id or Zi before the relay 220 can be set in motion to energize the solenoid |20 and start the pivotal movement. It is further readily apparent that the solenoid 0S cannot be energized to shift the directional control valve il! so as to admit fluid under pressure to the pivotal cylinder i'il until after the solenoid ||0 has been energized to withdraw the locking plunger |00, thereby closing the limit switch 22|.

The operation of this machine is readily apparent lfrom the foregoing disclosure. Assuming the parts to have been previously adjusted and the machine set up for grinding a given size piston ring or work piece i5, the machine is started by moving the control lever 'il to close the circuit which sets in motion the time relay '50 and energizes the solenoid 'i2 to initiate a forward feeding movement of the grinding wheel 30. When the wheel slideV starts its forward feeding movement toward the work, the abutment or cam 230 recedes from the normally closed limit switch 23| which closes a circuit to actuate a magnetic starter switch 232 which in turn starts the work driving motor |9 and energizes the solenoid 00 to open the pressure valve S8 so as to admit uuid under pressure to the di- The spring normally holds the directional valve 0| in an uppermoet position (Fig. 2) so that when the valve 80 is opened fluid under pressure passes through the directional valve 9| and out through the pipe 00 and through the table control valve |00 and through a pipe |00 into cylinder chamber H0 to move the cylinder 00 and the table attached thereto toward the right. As the table moves toward the right, the cam face on the bracket 20| carried by the shuttle table |35 engages the actuating member 2 4 actuates the normally open limit switch 2H which serves to set in motion vthe Microflex time relay 22B and `also to energize the solenoid Ifiii which in turn retracts the looking plunger |39 from its notch |38 in the swivel plate |25. At the same time, the directional control valve 9| is moved downwardly by energizing the solenoid dii. This movement of the valve 3| serves to cut cfr fluid from the pipe SS, thus stopping the movement of the `table |I, and passes iiuid under pressure through the pipe IsI to the swivel control rvalve unit |55 which conveys fluid under pressure through the pipe I'li into the cylinder chamber I'Il in the cylinder I'iil to move the piston V53 toward the right (Fig. 2) to grind the right-hand corner radius on the piston ring. IThe swivel frame 25 moves approximately through a 45 motion until the cam |59 on the arrow-pointed plate |53 engages the roller I 52 and shifts the bar @5 toward the right which in turn shifts the reversing valve by moving the reversing lever I2!) into the position illustrated in Fig. 1. This movement shifts the rod |38 so as to change the position of the reversing valve |81 to reverse the flow of fluid under pressure to the cylinder I-l'il, thus starting the swivelling df the work piece in the reverse direction.

` When thev reversing lever IZ is `shifted in either direction to reversethe valves |95 and |31,

Va hydraulically operated pawl and ratchet feed mechanism advances the wheel into the work for the return stroke. The time relay 220 which has energized the solenoid |49 is set to deenergize the solenoid Idil before the locking plunger |33 again reaches the notch |33 lin the plate |215 so that the end of the plunger |39 rides on the peripheral arcuate surface 223 of the plate |25. When the plunger |39 moves into alignment with the notch |32 and drops therein, this movement lserves to open thenormally open limit switch 22| which in turn serves to deenergize the solenoid Sii, allowing thefdirectional control valve Si to move upwardly, thus cutting oi uid under pressure from the pipe |9| and again admitting uid under pressure through the pipe 99 to the table control valve unitV I til. The reversing valve being interconnected with the reversing valve |31, has previously been shifted into its reverse position so that the fluid under pressure passing therethrough is conveyed through the pipe itil into the cylinder chamber |88 to move the cylinder lil and the table toward the left (Figs. 1 and 2).

The movement of the table II toward the left continues until lthe cam face of the bracket Eili engages the roller 2532 which serves to hold the shuttle table |35 stationary during the remaining movement of the table I! toward the left. The roller 2532 and bracket 2t@ serve to locate the left-hand corner radius center of the piston ring rbeing ground directly over the axis of the pivot stud |27. At the same time, the shuttle table adjusting screw 2i 'I closes the limit switch 2lb andthe main table dog M3 carried by the table II closes the limit switch 2M) which serves to again set the Microex time delay relay 225i in motion and to Venergir/l'e the solenoid |69 to again withdraw the locking plunger i253. The withdrawal of the 'locking plunger It from the notch |33 serves to close the normally open limit switch 22| which makes a circuit to energize the solenoid 96 which again moves the Vdirectional control valve downwardly to cut on fluid pressure from the pipe 99 to stop the movement of the table .I I and at .the same time to admit fluid under pressure through the pipe lei to the swivel con trol valve unit which admits fluid under pressure to the cylinder chamber |19 Vto produce movement of the piston |i'3 and piston rod Vl'l toward the left (Fig. 2) to swivel the frame |2 in a clockwise direction (Fig. 2) to grind the left-hand corner radius or fillet on the piston ring I5 being ground.

As the frame |25 approaches a 45 position, the cam face |59 moves into position |5912 in contact with the roller lI and continued movement swings the arrowhead member |53 into position I'Bc, during which movement the cam face lt moves into position I liic, moving the roller |5I toward the right into broken line position |5Ia. This movement of the roller |5| produces acorrespcnding movement of the slide bar toward the right, during which movement the notch lii in the slide bar M5 engages the stud |22 on the reversing lever |22 and shifts the reversing lever in a counterclockwise direction, which movement shifts the reversing valves Ii and |87 of the control valve units I@ and |35 so as to reverse the iiow of uid to the cylinder Il@ and vadmit fluid under pressure to the cylinder chamber Ill which swings the frame |25 in a counterclockwise direction (Fig. 2) to grind the left-hand corner radius again on its return stroke.

As the frame approaches its normal locked position, the time delay relay 225i operates to deenergize the solenoid It@ so that the end of the locking plunger |39 rides on the peripheral arcuate surface 223 of the plate |25. When the plunger |39 moves into alignment with the notch |38, the released compression-of a spring throws the locking plunger |29 into engagement with the notch |39, thus locking the frame |26 in position, with the work axis parallel to the wheel axis. During this locking movement the limit switch 22| opens, thus deenergizing the solenoid B5, at which vtime the electrical time delay relay i8 operates to deenergize the solenoid "I2, releasing the compression of the spring li which returns the speed control valve Sil to its reverse position to initiate a rearward feeding movement of the grinding wheel slide 3| to remove the wheel 3i? to an inoperative position. When the wheel slide reaches its rearmost position a detent on the slide y3| engages and opens the normally closed limit switch 23| which in turn opens a circuit to cut off the magnetic starter switch. The actuation of the magnetic starter switch serves to stop the lwork drive motor to facilitate removal of the ground work piece and the insertion of a new work piece there instead.

A limit switch 235 which is a normally open limit switch is arranged to be actuated in timed relation with the solenoid |41! in a manner Similar to the switch 22|. The limit switch 235 is connected in parallel with the limit switch 23| and serves to insure the swivel plate |26 returnn ing to its neutral position when the table stops above described may be repeated one or more times on a given work piece if desired, depending upon the setting of the time relay 13. In case one or more cycles are utilized, the limit switch 235 serves to maintain the circuit to the magnetic starter switch Iclosed until the swivel plate |26 has returned into a latched position with the plunger ISS in engagement with the notch |33 to complete the cycle of movement of the parts.

It will thus be seen that there has been provided by this invention apparatus in which the various objects hereinabove set forth together with many thoroughly practical advantages are successfully achieved. As many possible embodiments may be made of the above invention and as many changes might be made in the embodiment above set forth, it is to be understood that all matter hereinbeiore set forth or shown in the accompanying drawings is to be interpreted asillustrative and not in a limiting sense.

I claim:

l. In a grinding machine having a transversely movable rotatable grinding wheel, a longitudinally movable table, a pivotally mounted horizontally movable platen carried thereby, a rotatable work support on said platen, means to feed said wheel transversely toward and from said work support to produce a predetermined grinding feed, means to reciprocate said work table longitudinally to grind a cylindrical face on a work piece, means to swing said platen relative to said table during rotation of the work piece to produce a predetermined radius adjacent to the end of said cylindrical surface, and an interlocking mechanism between said table reciprocating mechanism and said swinging mechanism whereby one of said mechanisms is rendered inoperative while the other is in an operating position.

2. In a grinding machine having a transversely movable rotatable grinding wheel, a longitudinally reciprocable work table, a pivotally mounted horizontally movable platen carried thereby, a transversely adjustable slide on said platen, a longitudinally movable slide carried by said transverse slide, a rotatable work support including a headstock and a footstock on said longitudinally movable slide, means including a piston and cylinder to reciprocate said work table to grind a cylindrical face on a work piece, and means including a piston and cylinder operatively connected to swing said supporting platen during rotation of the work piece to produce a predetermined radius adjacent to said cylindrical face.

3. In a grinding machine having a rotatable grinding wheel and a rotatable work support which are movable longitudinally and transversely relative to each other, means including a piston and cylinder to cause a rela-tive transverse feeding movement between -said members, means including a piston and cylinder to cause a relative longitudinal traversing movement between said members, means including a piston and cylinder to swing one of said me ..-bers about an axis which is normal to a planer. passing through the axes of said member-s to grind a predetermined radius on the periphery of a work piece, and means including a directional control valve which is automatically actuated and is arranged to admit iiuid under pressure either to the traverse cylinder or to the swivel cylinder.

4. In a grinding machine having a rotatable grinding wheel and a rotatable work support which are movable longitudinally and trans- CII versely relative to each other, means normally to lock said wheel and work support with their axes parallel to each other, means to traverse said wheel and work support longitudinally relative to each other, means to cause a relative swinging movement between said wheel and work support about an axis normal to a plane passing through the axes of the wheel and work, electrically operated means to actuate said locking means, and electrically operated mechanism actuated by and in timed relation with said relative longitudinal movement to actuate said locking means to initiate a relative swinging movement between the v/heel and work support to grind a curved face on the periphery or" a work piece.

5. In a grinding machine having a transversely movable rotatable grinding wheel, a longitudinally reciprocable work table, a rotatable work support pivotally supported on said table which is arranged to swing about an axis normal to a plane passing through the axes of the grinding wheel and rotatable work support, means including independent iluid motors to actuate each of said element-s, separate reversing valves for each of said motors, a directional control valve to 'control the admission of iluid under pressure to said table and swinging motors, and means controlled by the transverse movement of said grinding wheel and the longitudinal movement of said table to actuate said control valve to initiate a swinging movement of the rotatable work support to grind a radius on the periphery of a work piece.

6. In a grinding machine having a transversely movable rotatable grinding wheel, a longitudinally reciprocable work table, a rotatable work support pivotally supported on said table which is arranged to swing about an axis normal to a plane passing through the axes of the grinding wheel and rotatable work support, means including independent fluid motors to actuate each of said elements, separate reversing valves for each of said motors, a directional control valve to control the admission of uid under pressure to said table and swinging motors, and an electrical interlock and control mechanism actuated by the transverse movement of the grinding wheel and the longitudinal movement of` said table to actuate said control valve to stop the table and to initiate a swinging movement of said work support.

7. In a grinding machine having a rotatable grinding wheel and a rotatable work support which are movable longitudinally and transversely relative to each other, a locking plunger normally to hold said wheel and work support with their axes parallel to each other, means including a solenoid to withdraw said plunger, means relatively to traverse said wheel and work support longitudinally relative to each other.. means to cause a relative swinging movement between said wheel and work support about an axis normal to a plane passing through the axes of the wheel and work support, and an electrical interlock actuated by and in timed relation with said longitudinal traversing movement to energize said solenoid to withdraw said locking plunger when the longitudinal traversing movement has completed its effective stroke.

8. In a grinding machine having a rotatable grinding wheel and a rotatable work support which are movable longitudinally and transversely relative to each other, means including a locking plunger normally to hold said wheel and work support with their axes parallel to each other, a feeding mechanism to cause a relative feeding movement between the wheel and' Work support to grind a cylindrical face on a work piece, a reciprocating mechanism to produce a relative longitudinal movement between the wheel and work support, means to cause a relative swinging movement between the wheel and Work support about an axis normal to Va plane passing through the axes of the wheel and work support to grind a radius or fillet on a work piece, an electrically controlled mechanism to produce rst a relative longitudinal movement between the wheel and work support and then a relative swinging movement therebetween, and means actuated in timed relation with said swinging movement to reverse the direction ci said swinging and longitudinal movement.,

9. In a grinding machine having a transversely movable rotatable grinding wheel, a longitudinally reciprocable tab-le, a pivotally mounts platen carried thereby, a transversely adjustable slide on said platen, a longitudinally movable table carried by said transverse slide, a rotatable work support including a headstock and a footstock on said shuttle table, means including a piston and cylinder to reciprocate said worr table longitudinally to grind a cylindrical surface on a Work piece, means including a piston and cylinder operatively connected to swing said platen during rotation of the work piece to produce a predetermined radius on the work piece adjacent to said cylindrical surface, a directional control Valve to admit fluid under pressure either to the table traverse cylinder or to the plate swinging cylinder, and means actuated by and in timed relation with said table to actuate said valve to stop the work table and to initiate a swinging movement of said platen relative to said table.

10. In a grinding machine having a transversely movable rotatable grinding wheel, a longitudinally reciprocable work table, a pivotally mounted platen carried thereby, a transversely adjustable slide on said platen, a longitudinally movable table carried by said transverse slide, a rotatable Work support including a headstccl: and a footstock on said longitudinally movable slide, means normally to lock said plate with the' axis of the work support parallel to the axis of the grinding wheel, means including a piston and cylinder to reciprocate said table longitudinally to grind a cylindrical surface on a Work piece, means including a piston and cylinder operatively connected to swing said platen during rotation of said work support to produce a predetermined radius on the work piece adjacent to said cylindrical surface, a directional control valve to admit fluid under pressure either to the table traverse cylinder or to the platen swinging cylinder, and means actuated by and in timed relation with said table to unlock said platen and to actuate said control valve to stop said work table and to initiate a swinging movement of the work support relative to said table.

11. In a grinding machine having a transversely movable rotatable grinding wheel, a longitudinally reciprocable Work table, a pivotally mounted platen carried thereby, a transversely adjustable slide on said platen, a longitudinally movable slide carried by said transverse slide, a rotatable work support including a headstock and a footstock on said longitudinally movable slide, means normally to lock said platen with' rthe axis of the work support parallel to the axis of the grinding wheel, means including a piston and cylinder to reciprocate said table longitudinally to grind a cylindrical surface on a wort: piece, means actuated by and in Vtimed relation with the longitudinal movement oi the Werl: table to unlock said platen, means including a piston and cylinder operatively connected to swing said platen during rotation of the work piece to produce a predetermined curved face on the work piece adjacent to said cylindrical surface, and means including a directional control valve which is automatically actuated and is arranged to admit fluid either to the table cylinder or to the platen cylinder, whereby said cylindrical face may be ground while the table is traversed and said radius may be ground thereafter by the swinging movement of said supporting platen while the table remains stationary.

12. In a grinding machine having a transversely movable rotatable grinding wheel, alongitudinally reciprocable work table, a pivotally mounted platen carried thereby,`a transversely adjustable slide on said platen, a longitudinally movable slide carried by said transverse slide, a rotatable work support including a headstock and a footstock on said longitudinally movable slide, means including a piston and cylinder to reciprocate said table to grind a cylindrical suface on the Work piece, means including a piston and cylinder operatively connected to swing said supporting plate during rotation of the work piece to produce a predetermined radius on the work piece adjacent to said cylindrical surface, a table actuated reversing valve to control the flow of fluid under pressure to said table cylinder, and a second reversing valve actuated by and in timed relation with the rst valve to control the flow of fluid under pressure to said supporting plate cylinder.

13. In a grinding machine having a trans-l versely movable rotatable grinding wheel, a longitudinally recip-rocable work table, a pivotally mounted platen carried thereby, a transversely adjustable slide on said plate, a longitudinally movable slide carriedv by said transverse slide, a rotatable work support including a headstocli and a footstock on said longitudinally movable slide, means including a piston Vand cylinder to reciprocate said table to grind a cylindrical surface on the work piece, means including a piston and cylinder operativelyrconnected to swing said supporting plate during rotation of the Work piece to produce a predetermined radius on the work piece -adjacent to said cylindrical surface, a table actuated reversing valve to control the now of uid under pressure to said table Cylinder, a second reversing valve actuated by and in timed relation with the first valve to control the flow of fluid under pressure to said supporting plate cylinder, and means actuatedby the swinging movement of said platen to actuate said reversing valves. Y

14'. In a grinding machine having a transversely movable rotatable grinding wheel, a longitudinally movable table, means to reciprocate said table, a longitudinally movable shuttle table supported on said table, a rotatable work support on said shuttle table, means to cause a swinging movement of said shuttle table `relative to said longitudinally movable table about an axis normal to a plane passing through the axes of the wheel and work support to grind a radius or nllet on the Work piece, and means to limit the longitudinalv movement of said shuttle table to position the work piece With the center of said radius aligned with the pivotal axis.

15. In a grinding machine having a transversely movable rotatable grinding wheel, means to feed said Wheel transversely, a longitudinally movable table, a pivotally mounted horizontally movable platen on said table, a rotatable Work support on said platen, means to reciprocate said 

